Expansive thread cutting die and stock



Sept. 10, 1935. T. L. DAGG EXPANSIVE THREAD CUTTING DIE AND STOCK Filed Dec. 26, 1934 2 Sheets-Sheet 1 @aitt Lagfiqyy ATTORNEY WITN ES! Sept. 10, 1935. T, DAGG 2,014,312

EXPANSIVE THREAD CUTTING DIE AND STOCK Filed Dec. 26, 1954 2 Sheets-Sheet 2 Patented Sept. 10, 1935 EXPANSIVE THREAD CUTTING DIE AND STOCK Truitt L. Dagg, Goliad, Tex. Application December 26,1934, Serial No. 759,276

4 Claims.

The invention relates to a thread die and stock and more especially to an expansive thread cutting die and stock.

The primary object of the invention is the provision of a thread cutting implement or tool of this character wherein, through the use of an eccentric, the thread cutting dies as fitted Within the stock can be expanded and in this assembly standard threads and oversize threads may be conveniently cut in the use of the implement or tool.

Another object of the invention is the provision of an implement or tool of this character, wherein when the same has been used for outting threads it can be readily removed from the piece of work without requiring the backing of such implement or tool on the threads out thereby-and the thread die may be expanded for the placing of the same upon a thread previously cut, so that by backing the tool off of the thread the same where battered or upset will be refinished and cleaned with a true straight thread.

A further object of the invention is the provision of an implement or tool of this character, wherein the same is equipped with a micrometer so'that determined adjustment of the dies can be had in the use of the implement or tool for thread cutting.

A still further object of the invention is the provision of an implement or tool of this character, which is simple in construction, thoroughly reliable and efficient in its purpose, readily and easily adjusted for the cutting of standard and oversize threads, strong, durable, easy of operation, and inexpensive to manufacture.

With these and other objects in view, the invention consists in the features of construction, combination and arrangement of parts as will be hereinafter more fully described in detail, illustrated in the accompanying drawings, which disclose the preferred embodiment of the invention, and pointed out in the claims hereunto appended.

In the accompanying drawings:

Figure 1 is a fragmentary perspective view of a stock and die assembly constructed in accordance with the invention.

Figure 2 is an enlarged sectional view on the line 2-2 of Figure 1 looking in the direction of the arrows.

Figure 3 is a fragmentary sectional view taken approximately on the line 3-3 of Figure 1 looking in the direction of the arrows.

Figure 4 is an exploded perspective view of the collet, cutting die, eccentric ring and guide.

Figure 5 is a fragmentary sectional view on the line 5-5 of Figure 3 looking in the direction of the arrows.

Figure 6 is an elevation of one of the thread cutting dies.

Similar reference characters indicate corre- 5 spo-nding parts throughout the several views in the drawings.

Referring to the drawings in detail, A designates generally a thread cutting die stock and B portions of the handles which are extended from 10 opposite ends of the said stock. This stock A has the open circular center I0 for the fitting therein of a collet II, it having the flanged end i2 engaged in a seat l3 as provided in the open center H} at one side of the stock. This collet 15 H has detachably connected therewith a work guide M which is of conventional form for the guiding of a pipe or rod to be operated upon for the cutting of threads therein, the guide l4 being detachably secured to the collet through the me- 20 dium of the cap screws l5 which are countersunk in the guide at the outer face thereof. This guide 14 is formed with external threads I6 for the separable connection therewith of a threaded retaining ring ll which overhangs the stock and 25 in this fashion the said collet I I and guide M are made secure in the circular portion 10 of the stock A, as will be apparent from Figures 2 and 3 of the drawings.

The collet has formed therein diametrically opposed radially arranged guide openings or slots H! for thread cutting dies 19, the latter and the said openings or slots 18 being provided with shoulders 20 and 2 l respectively, which are companions to each other in the fitting of the dies I!) with the collet H, so that said dies will have trackage in the openings or slots l8 for their sliding radially in the collet ll.

Disposed within an annular guideway or seat 22 provided in the circular portion ID of the stock 0 and concentrically of the collet l l is an eccentric ring 23 having the internal series of eccentrics 24, each, eccentric 24 of the series being provided with the pair of cam faces 25 and 20, respectively, these being on different radius line to the center of the eccentric ring and such surfaces being adapted for action upon the dies IQ for the expansive action of the same in the use of the implement or tool.

The dies I9 have the heel extensions 21, each being provided with a channel or groove 28 for a split tensioning ring or spring 29 which is disposed concentrically of the collet II and is engaged with the respective dies l9 to urge the 55 same outwardly for expansive action in the operation of the eccentric ring 24.

The circular portion H] of the stock is provided with an annular clearance 30 for the ring or spring 29 to avoid interference in the expansive action thereof.

The circular portion In of the stock H at one side thereof is provided with an elongated adjusting cap screw slot 3| in which is fitted an adjusting screw slide block 32 fitted with the adjusting cap screw 33 which is threaded in the eccentric ring 23 so that the latter can be turned for the expansive action of the dies l9 and such screw 33 will lock the eccentric ring in its adjusted position. The slide 32 has an indicator mark 34 thereon cooperating with a graduated micrometer scale 35 as provided exteriorly on the circular portion In of the stock A, so that accuracy may be had in the adjustment of the eccentric for the setting of the dies I9 under expansive action thereof. p

The slot 3| is also fitted with a slide stop 36 carrying an adjusting cap screw 31 which engages a lock nut 38, the head of the screw being slidably fitted in an undercut 39 in the circular portion ID with respect to said .slot 3|, and this stop 36 can be readily and conveniently set with respect to the scale 35, it being provided with an indicator 40 for coaction with the scale 35 and such stop locked in its set position to limit the adjustment throw of the slide block 32 for accuracy in the setting of the dies IS on adjustment of the eccentric ring 23 as the slide block 32 canbe brought to the stop 36 under the ad justment thereof with respect to the scale 35 and thus accuracyhad in the adjustment of the dies.

The stock and die assembly is operated in the conventional manner of a standard stock and die assembly.

The faces 25 and 26 of the eccentric 24 of the ring 33 afford minute and a wide range of expansive action of the dies under adjustment of the eccentric ring 23.

The slide block 32 with the screw 31 affords a micrometer stop for accuracy in the setting of the implement or tool as will be apparent.

What is claimed is:

1. A tool of the character described comprising a stock having a circular opening, a flanged seat provided in said opening at one side of the stock, a collet fitting said opening and having a flanged end engaging said seat, a work guide detachably connected with the collet, radially ar- 5 ranged adjustable thread-cutting dies fitting said collet, and an eccentric encircling said collet and having series of pairs of cam faces for action upon the dies for expansive action of the same.

2. A tool of the character described compris- 1O ing a stock having a circular opening, a flanged seat provided in said opening at one side of the stock, a collet fitting said opening and having a flanged end engaging said seat, a work' guide detachably connected with the collet, radially arranged adjustable thread-cutting dies fitting said collet, an eccentric encircling said collet and having series of pairs of cam faces for action upon the dies for expansive action of the same, and means holding the dies in working relation to the pairs of cams of the eccentric.

3. A tool of the character described comprising a stock having a circular opening, a flanged. seat provided in said opening at one side of the stock, a collet fitting said opening and having a flanged end engaging said seat, a work guide detachably connected with the collet, radially arranged adjustable thread-cutting dies fitting said collet, an eccentric encircling said collet and having series of pairs of cam faces for holding the dies in working relation to the pairs of cams of the eccentric, and adjusting means for the eccentric.

4. A tool of the character described comprising 35 a stock having a circular opening, a flanged seat provided in said opening at one side of the stock, a collet fitting said opening and having a flanged end engaging said seat, a work guide detachably connected with the collet, radially arranged ad- 401 action upon the dies for expansive action of the same, means 

